Bridge deck finisher



Dec. 15, 1964 B. l.. LARSEN ETAL BRIDGE DECK FINISHER 2 Sheets-Sheet l Filed May 24, 1961 IN1/EN Tons Earn/zam L. Larsen B. L. LARSEN ETAL BRIDGE DECK FINISHER 2 Sheets-Sheet 2 INVENTORS 5dr/#24M Z. arse/1 BY 5er/fara .Z laffe/r www f ATTORNE Dec. 15, 1964 Filed May 24 1961 3,161,115 BRHDGE DECK FENESIER Burnham L. Larsen and Bernard Li. Larsen, both of Cedar Falls, Iowa, assignors to (Iurhmaster ot America, ine., Cedar Fails, iowa, a corporation of Iowa Filed May 2d, i9d, Ser. No. ild l Ciaim., (Cl. iid-45) This invention relates to apparatus for .finishing concrete slab which is placed on bridges, overpasses and the llike in connection with highway and roadwork, and more particularly to a bridge deck finisher which is simple in construction, light in `weight and easily assembled by hand labor. t f

Heretofore, there has been no simple and eective bridge deck finisher which could accommodate factors such as the carnber and crown of the deck while furnishing the power required for finishing;

The present invention satisfies these requirements by means of a bridge deck finisher utilizing two power or propulsion units, each of which units has four wheels for traveling on twin rails with each of the wheels providing traction. This construction enables each of the power units to be self-supporting so that it can stand by .itself during assembly of the bridge deck finisher. Further in accordance with the invention, self-supporting concrete screeds are attached between the power units in spaced relation to one another, by swivel means which relieve the individual power units of any side pull or strain. And the screeds are connected to the swivel units by hydraulic cylinders mounted on the ends of the screeds so that the screeds may be lifted from the concrete as required. n l

In order to render the concrete screeds self-supporting while enabling any desired amount of crown to be pro- United States Patent C vided therein, raised flanges are welded transversely and at predetermined intervals along the top surfaces of the screeds, and continuously threaded rods are passed through the lianges with nut elements on each side of each of the flanges. Thus by exerting suitable pressure on the nut elements it is possible to shape vthe rectangular screed to its desired crown while the rods themselves yact as trusses for the screeds. The front screed has a shield attached to the front portion thereof which prevents the concrete from pushing back up onto the threaded rods. Also, the front screed i-s desirably vibrated by variable speed vibrators secured thereto so as to compact the concrete and leave a smooth finish. By changing the speed of the vibration the correct amount of concrete may be made to pass underneath the screed. The rear screed also has a shield which provides a greater surface sliding on the concrete than does the front screed and is in effect a trowelling pan which gives the exact desired contour and finish to the concrete. The front and rear screeds are also connected by braces which are dropped into place when the machine is assembled. Thus the bridge deck finisher of the invention can be assembled and disassembled in a minimum of time using only hand labor.

In'order that therails for the individual power units may be set to the exact carriber shown in the bridge design, to within a fraction of an inch, pedestals or supports for the rails are provided having threaded main idii Patented Dec. 15, i964 sections which in turn are threadedlinv collars on the rails. The base part of the pedestals may be left in the concrete where suitable.

Accordingly, it is an object of the present invention to provide a bridge deckfinisher which is simple in construction, light in weight and easily assembled by hand l labor.

Another object of the invention is to provide a bridge deck finisher as described which is exceptionally powerful and has a high degree of traction as afforded by individual power units. l

Another object of the invention is to provide front and rear screeds connected to they power units by swivel means so that the individual power units arerelieved of any side pull or strain.

Another object of the invention is to provide screeds as described which are mounted to the power units hydraulically so as to permit them to bek raised and lowered as required.

Another object of the invention is to provide truss means for imparting a desired crown to the screeds.

Another object of the invention is to provide means for finishing the concrete at a desired contour.

Another object of the invention is to provide a device as described which assures that the desired amountrof concrete will pass under the screeds.

.Another object of the invention is to provide rail means for the power units which are adjustable to the exact cam-ber of the bridge design and to within a fraction of an inch.

Other objects and advantages of the invention will become apparent as the description proceed-s in accordance with the drawings in which Y FIGURE 1 is a perspective view of a bridge deck finisher in accordance with the present invention, partly in exploded form;

FIGURE 2 is a -top plan view of rail means for the finisher of the invention;

FIGURE 3 is a side elevational view of the rail means in operational relationship with adjustable pedestal means therefor;

FIGURE 4 is a schematic top plan view, partly broken away of the finisher and rails in tracking relationship; FIGURE 5 is a vertical sectional View of the front Vscreed structure Ifor the device of the invention; and

. with four traction wheels 13 and 114 respectively. .The

f traction wheels are dimensioned to run on double rails l5 adjustable by pedestal means 1d as hereinafter further described. Front and rear screeds ll7 and 18 are connected between the individual power units il and liZ by individual hydraulic means i9 and swivel connections 2). lnrorder to afford a desired crown for the screeds, threaded truss I rods 21 are received in spaced apart braced iianges 22 welded to the top surface of each of the screedsll and 18. To this end, nuts 23 are placed on each `of the rods 2i) on each` side of each of the flanges 22 so that by exerting pressure on these nuts it is possible to shape the screed toa desired crown ashereinafter further described. lnrorder to prevent concrete from backing up onto the threaded rods 21 of the front screed 17, a shield 24 is secured to the front of the said screeds and has an upstanding, forwardly turned flange 25 for this purpose. Likewise, the rear screed 18 has a sliding surface 26 of greater surface area than the front screed so that it in effect acts as a trowelling pan which gives the exact desired contour and finish to the concrete.

In order to brace the screeds, support braces such as the brace 27 are dropped into place on the apparatus when the machine is assembled. The braces may be secured to suitable support means on one or more of the flanges 22. The front screed 17 has one or more variable speed vibrators 28 attached thereto and poweredv from generator means or the like (not shown) carried on the machine 1l) or otherwise so that by vibrating'the screed the concrete is compacted and a smooth finish is aorded; while by adjusting the speed of vibration the correct amount of concrete is permitted to pass underneath the screed.

The individual power units 11 and 12 may each include a motor 29 which may be powered from the generator means and connected to a gear box 30 operating individual sprockets (not shown) for driving front and rear wheels by chain means (not shown) which may be covered by guards 31.

In assembling the device, the two power units 11 and 12 are set on their respective rails or tracks 15, and the screeds 17 and 18 are then placed in their respective positions as shown and attached to the power units as by pins 324 connected to the hydraulic means 19 and by pins 33 connected to the swivel means 20 and having a ball joint connection or the like in a housing 34 on the power units. Thereby, any side pull or strain on the power units is obviated and both the front and rear screeds may be lifted from the concrete by the hydraulic cylinders as required. When the front and rear screeds have been attached to the power units, the supporting braces 27 may then be dropped into place.

Since the deck floors of bridges andthe like not only have crown but also camber, the rails 15 -must be set precisely in accordance with the bridge design. The pedestal means 16 accomplish this purpose to within a fraction of an inch, by means of base elements 35 threadedly receiving main pedestal sections 36 which in turn are threaded into selected collars 37 secured in proximately axially spaced relation to a shoulder or ledge 38 on the rail by welding or the like in opposed individually axially spaced groups as shown. Accordingly, plurality of these pedestal means 16 may be set along the individual rails on each side thereof and adjusted as required in accordance with the camber ofthe bridge design. Thus the main sections may be turned into or out of the threaded basesv of the pedestals to achieve the' desired elevation, and after the bridge deck finisher has completed its operation, the rails may be removed and the main sections 36 of the pedestals turned out of their bases 35 and used again. The bases 35, however, may be left in the concrete if the bridge design is such that the concrete may be poured on the part of the deck on which the pedestals are set. Suitable hopper means (not shown) for pouring may be set on one of the-power units 11 and 12. The twin rails 15 will be set to grade on the form work of the bridge deck prior to the pouring of the concrete for the bridge as understood by those skilled in the art.

The four wheels for each of the power units 11 and 12 accomplish two purposes. First, the individually driven wheels transmit more traction to the rails for the movement of the machine than would ordinarily be possible. The quadruple wheels also enable each power unit to be self-supporting so that the individual power units will stand by themselves during assemblage of the machine 10 on the rails 15.

The concrete screeds 17 and 1S may be self-supporting and still enable any required amount of crown to be set into the screeds, by means of the welded braced flanges E 22, which are spaced apart at predetermined intervals along the top surfaces of each of the screeds for this purpose. By exerting pressure on the nuts 23 on each side of each of the flanges, the threaded truss rods 21 shape the rectangular screeds to their desired crown. As also indicated, the rods 21 serve as trusses on the screeds.

Thus the device has a basic design which enables it to be assembled and disassembled in a minimum amount of time, and by using only hand labor. The front and rear screeds are readily placed in their respective positions and attached to the power units by means of the two pins 32 and 33 on each end of each of the screeds, which are connected to the hydraulic cylinders 19 and the swivel connections 20 respectively. And when the screed braces 27 have been dropped into place as described, the machine is ready to operate.

The bridge deck finisher 10 of the invention may also travel in either direction along the rails 15, since the electric motor means 29 which power this unit are desirably reversible, by means of a directional switch mounted on a control panel (not shown).

Accordingly, a bridge deck finisher has been provided such as to afford advantages over any previously known or presently available apparatus, by virtue of its unusual simplicity of construction, lightness in weight and ease of assembly by hand labor.

Although We have herein set forth and described our invention with respect to certain specific principles and details thereof, it will be understood by those skilled in the art that these may be varied without departing from the spirit and scope of the invention as set forth in the hereunto appended claim.

We claim as our invention:

An elongated deck finisher for use infinishing concrete slab or the like on bridges, overpasses and the like comprising, 4

a pair of upright power driven units each of which is situated on one side of the longitudinal axis of the finisher,

said power driven units each being self-supporting for assembly in place on a bridge or the like and each comprising,

elongated Wheel mounting means extending parallel to the longitudinal axis of the finisher and at least four wheels mounted on each of said wheel mounting means with pairs of wheels situated at the front and the back of the power unit and with wheels of 'each pair spaced transversely of each other such that each power unit is capa'- ble of supporting itself in an upright position,

power means on each of said power units for driving the wheels,

a transversely extending screed removably interconnecting the power unitsfand comprising an elongated cross-sectionally substantiallyy rectangular structure,

a plurality of upstanding transversely spaced flanges mounted alongthe upper surface of said screed,

a pair of continuously threaded truss rods extending substantially parallel to said structure and passing through said flanges, and means threaded complementarily to and carried on said rods and engaging each of said flanges, said means' being adjustable on said rods to move said flanges relative to said rods whereby to impart a desired crown to said screed, and

swivel means at each end of said screed'for selectively removably joining the screed to each of said power units and comprising a ball joint connection carried by each of said power units,

a pair of horizontal pins rotatably connected respectively to said ball joint connections,

References Cited by the Examiner UNITED STATES PATENTS 3/ 02 Beecher 23 8-122 4/ 14 Sande 23 8-122 8/21 Baker 94--45 McCrery 94-45 Sarosdy 9445 Heltzel 94-45 Nave 94-48 Apel et al 94-45 Hudis et al 94-45 Melvin et al 94-45 Oster 94-45 Neil 94-45 1 BENJAMIN BENDETr, Primary Examiner.

JACOB L. NACKENOFF, Examiner. 

